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With the advent of automated closure systems have come new benefits as well as new risks. For instance, in vehicle applications, power windows equipped with xe2x80x9cexpress closexe2x80x9d capability enable an operator to close a window with a brief activation of a window control switch. This enables a driver to return both hands to the steering wheel quickly. Express close capability has also found use in enabling convenience features such as automatic venting of a vehicle and automatic window closure upon detection of rain, motion, or a command from a remote signaling device such as a key fob.
However, the possibility exists that an obstacle may be present in the path of a window which has been commanded to express close. Absent failsafe features, such an obstacle may be struck by the closing window and pinned against the surrounding trim. Sufficient force may be applied by such a window to entrap children, pets or fragile, oversized articles extending from the window aperture.
Contact-based systems were initially developed to detect the presence of an obstacle in the path of an express closing window. Such contact-based systems include window motor-monitoring systems. which may monitor the frequency of window motor operation over a given period of time by tracking characteristics present in the motor drive current. Alternatively, the number of revolutions of the window motor may be correlated into a description of the window travel distance. If it is determined that the window has not traveled far enough over a given time period, an obstacle may have been detected. Other contact-based systems have been employed, including various resistive systems which monitor the electrical characteristics of a circuit disposed either along the edge of a closure such as a window, or along the fixed surface against which the closure contacts when fully closed. The obvious detriment in such systems is the necessity that contact and entrapment with an obstacle must occur for there to be obstacle detection.
As an alternative, non-contact obstacle detection systems have been proposed. Such systems typically generate an energy curtain across all or a substantial portion of the aperture in which the closure travels, and a receiver monitors the state of this energy curtain. When an obstacle enters the aperture, a disruption in the energy curtain is observed by the receiver and the automatic closing of the window may be inhibited.
A variety of detection systems have been proposed, such as those employing infrared or ultrasound emitters and receivers. Plural emitters and receivers have been proposed, either co-located in a single housing or distributed about an aperture. However, they have typically been utilized to monitor most if not all of the aperture, with no selectivity, regardless of whether one or more portions of the aperture may be more or less important in terms of obstacle detection and overall system performance.
Consequently, it would be desirable to have a non-contact based obstacle detection system which would provide the flexibility to monitor one or more selected regions of an aperture, depending upon the conditions associated with the aperture.
A system and method are disclosed for enabling the selective monitoring of various regions of an aperture having a powered closure operative therein. In one embodiment, plural emitters are disposed within a common housing. Each emitter is adapted to provide a relatively narrow beam whose angle with respect to a horizontal plane is offset from the other emitters. Preferably, the radiated energy from all emitters covers substantially all of the aperture due to a certain degree of overlap between consecutive radiated fields. All of the radiated fields lie in substantially the same plane in azimuth. Thus, the detector system is capable of providing an energy field proximate any portion of the target aperture.
Associated with this embodiment of the invention is a controller which is capable of responding to certain stimuli and in response to selectively activate one or more of the co-located emitters. The energy curtain thus produced is monitored by a receiver which is preferably disposed within the same housing. The receiver output is then provided to the controller, which is capable of determining whether the receiver output is indicative of the presence of an obstacle in that portion of the aperture which was illuminated by the selected emitter or emitters.
A variety of systems may provide input to the controller for the purpose of influencing which of the plural emitters are to be activated for obstacle detection. Exemplary inputs to the controller include: vehicle ignition status; express close activation indication; window position information; vehicle climate control system data; inputs from rain, temperature, light, or motion sensors; and vehicle alarm system status. Thus, if a vehicle is running, an operator has commanded a window closed via an express close function, and the window is two-thirds of the way up already, the only important portion of the aperture from an obstacle detection standpoint is the remaining one-third of the open aperture. The controller may utilize the inputs as above to activate only those emitters which provide a radiation field across this upper portion of the aperture. The receiver is then operative to monitor the reflected energy and provide an output to the controller for obstacle detection.
A further example involves an indication to the controller that the vehicle is off, that the vehicle alarm system is active, and that the windows have been automatically lowered as a result of an automatic hot air venting function. It is preferable to monitor only the portion of the window which is open for venting purposes in order to minimize current drain on the vehicle battery.
In an alternative embodiment, one emitter may be used to illuminate proximate the aperture, and plural receivers, each having a limited field of view, are selectively activated to monitor the desired aperture portion. Thus, assuming the vehicle is running and an operator has commanded an express close of a window which is already two-thirds raised, it would be desirable to monitor only the upper third of the open window by activating a receiver whose field of view encompasses that portion of the aperture.
In a further embodiment, plural emitters and plural receivers are provided, all being independently selectable by the controller.
Regardless of specific implementation, the fundamental aspect of the presently disclosed invention is the ability to selectively monitor a discrete portion or portions of an aperture based upon a variety of factors. Flexibility in terms of response to detected conditions is also enabled.